Drawing apparatus.



BAIBNTED we. 14, 1906.

S. H. BONALDSGER DRAWING APPARA'HES'.

AHLIOAHGX rum) ms. 0,

I: lQtikiiEltllll zineqsea.

"It "all"; Fl?! Rs 60., WAJNI new". a. c.

UNITED STA ES PATENT oFFro'E.

DRAWlNG APPARATUS.

Specification of Letters Patent.

Patented Aug. 14, 1906,

Application filed March 10,1906. Serial No. 305,338.

To all whom it may concern.-

Be it known that I, SIDNEY HERBERT DON- ALDSQN, a subject of the King ofEngland, residing at 6 Boundary road, South Hampstead, in the county ofLondon, England, have invented certain new and useful linprovements inDrawing Apparatus; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to a new and improved drawing appliance of thenature of a T-square for use on a drawing-board for architectural,mechanical, or such like drawing or work.

The invention refers to a drawing appliance of the type of Tsquare inwhich the arm or blade is pivoted on a suitable upright post and isallowed to swing in any position there from in or out of right angles tothe upright edge of the drawing-board.

In the usual form of my invention I provide a longitudinal perpendicularguide-bar, having, by preference, a V-groove in each side of such bar orthe like. Above the said bar and extending on each side of it is aplatform oi plate carrying a center upright post with side pieces fixedunder the platform, with corresponding V-grooves running parallelassesso Into these grooves" I place antifriction steel balls, which arealgrooves in the guidebar.

lowed to occupy all the space between the grooves in the guide-bar andthe grooves in metal side pieces on the under side of the platformbefore mentioned.

One of the side pieces, with its groove for the ball-race, is madeadjustable by means of screws or the like to take up the wear on itsgroove and also on the groovesof the nichebar. In order that the boltsmay run eely,

so as to enable the platform carrying the W blade to run easily up anddown the guidebar, I make channels oi V, tubular, or other sections allround the side pieces before mentioned, so that the balls may runcontinuously round, making a complete circuit outside the pieces, theballs coming in contact with the guide-bar in the inner side of the saidside pieces and being keptin the grooves on the side pieces by means ofthe tubular or other section of casing or covering. The platform" beforementioned has a longitudinal move ment on the guide-bar by means of theball;

bearings, as before mentioned, and has piv oted upon the central uprightpost fixed on the platform a blade or arm somewhat of the shape and sizeusual in a T-square.

On the top edge or other suitable position I place along strip ofserrated metal, having the teeth on the upper edge overlapping the edgeof the blade. that in drawingperpendicular lines down the sheet of paperthe point of the pencil may be placed in the teeth and the platform andblade run easily and rapidly from top to betable position thereon. Theserrated band or strip may he graduated to any desired scale, and theremay be center-punched marks or other holes or indentations thereon toenable portionof an are from any point,

The 'oenter post is tapped inside and out. $orcwing on the outside is astrong handle ,nhicli upon a slight movement locks the blade upon theplatform, while still allowing a perpendicular motion of the platformand blade up and down the guide-ban" The looking enables the operator toretain'any desired "angle. 7 W There may be a flat scale or strippivoted underthe blade, extending beyond the serrations, thus enabling astraight line to be drawn by means of the straight edge of the fiatstrip. This strip is removable and is pivblade by means of a wing-nut orother device,

with regard to the top or bottom edge of the said blade. A pointer andscale may also indicate the angle between the bar and the extension ofthe si'nsil end of the said blade. This strip or bar'gives' a series ofangles from points re ressions; be possible to obtain with the bladealone, and vanishing-points can be obtained above and below the blade.

The upright post on the platform, which icons the pivot on which theblade works, 'may'be drilled and tapped through vertically, a milledscrew engaging therein, so that when the said screw is turned the lowerpart of'it ressesdown on the uidebar,thusinaking t e blade to be hel ator pivoted on a fixed position upon the said guide-bar.

V Iii order to indicate the exact angle of the blade in regard to theguide-bar or edge of thedrawingboard, I key upon the upright center posta fine-toothed wheel and engage therewith a pinion pivoted upon the topplate which forms the extension of the blade,

oted at the right hand or smaller end of the The object of these teethis,

tom of the paper or to or from any other suitthe point of a compass todescribe an are or which allows it to be set at any desired angle bladeby means of graduations merited on 7 show details of with a dial or itsequivalent fixed upon the inion and an indicating-pointer upon the backextension of the blade. The smallest movement of the said blade is thusindicated by the rotation of the dial by means of the enga ement of thepinion with the toothed whee before mentioned, thus enabling very finemeasurements to be registered. The blade has at or near its smaller enda slot or series of slots, so as to enable the operator to arrive at avanishing-point with great facility simply by putting a pin through theslot into the board where required, lowering the lefthand or slidingplatform of the apparatus while drawing the lines. A pointer attached tothe platform enables the vertical osition of the blade to be accuratelyde med by means of the graduations on the guide-bar. I

may also provide a dovetailed slot in the said guide-bar and have aseries of movable scales which can be readily slid into the aforesaiddovetailed slot in the said guide-bar, and

thus the scales can be varied according to the class of measurement orwork required. Provision may be made, if necessary, for the addition ofscales of various graduation to be attached to or form part of the bar,which is attached to the under surface of the blade, as

before indicated.

One or more snap-springs are provided under the upper blade to retainthe lower strip or bar in its closed position when in use. When desired,an additional small scale can be pivoted upon the top bar or any otherconvenient position, so that when the bar is raised or lowered at anangle to the blade and it is wished to draw a series of lines of varyingangles, but at given distances between such lines, these distances maybe easily regulated by means of the graduations upon this small pivotedbar, which may be brou ht down at 1 ht or any other angle to the ar andthe ind ications read from the line of contact with the top edge of theblade proportionately, and in order that this invention may beunderstood I will proceed to describe the same with reference to thedrawings accompanying this specification, in which Figure 1 18 a topplan of the apparatus. Figs. 2, 3, and 4 are details hereinafterreferredto. Fig. 5 shows alternative construction of portion of theapparatus. Figs. 6 and f such alternative construc- 1 tion. Figs. 8 to13 show further details of 4 construction hereinafter referred to.

The same letters and numerals of reference are employed to denote thesame parts in all the views.

a shows a guide-bar, which in the instrui ment shown is T-shaped incross-section, the l portion b being provided with screw-holes c, Iwhich serve the purpose of screwing the bar onto the side of adrawing-board or the like. i The portion a has V-grooves d in each edgethereof.

e is a platform or plate carryin a center upright post f. This plate orplat 'orm a has attached to its under surface two pieces 9, comin oneach side of the V-grooves of the guidear a. This may be suitably shapedto take into the said V-grooves d, or, as in the case of theinstrumentshownin the drawings, they may constitute chambers provided with. balls71, such balls projecting through grooves in the sides of the chambers,so that two ballraces are formed, one on each s de of the uide-bar a,which is therefore enabled to slide ongitudinally with great facility.The construction of this part will be clearly understood from Figs. 8,9, and 10, and it will be observed that in the case of the instrumenttherein represented the balls h are placed in a channel forming acontinuous ball-race in the chambers forming the side pieces g. The sidepieces of chambers g are secured to the under side of the platform e bymeans of screws 7c. One of the chambers g is provided with other screwsm. The heads of these screws m are mounted eccentrically, so that byrotating the screws the piece 9 is brought nearer to or farther from theedge of the guide-bar a. in order to enable the piece 9 to be adjustedin order to allow for wear. These screws m are shown in Fi s. 11 and 12.a is a blade somewhat resemb ing the blade of an ordinary T-square. Thisblade at in the case of the instrument shown is attached to a plate 1),which turns u )on the upright or postf, attached to the pl atform e. Theupright f is provided with a screw-hole and with a screwthread on theoutside. I prefer to have the screw-thread on the outside left-handed. ris a handle screwing on the outer thread of the upright post f. Whenthis handle is screwed down, the blade n is locked in any requiredposition, owing to the plate p being forced down upon the late orplatform 6.

s is a screw provided with a milled head t. This screw 8 screws into thescrew-hole inside the post or upright f and on account of its pressureupon the (guidebar a locks the plate 6 at any require position along thesaid guide-bar a.

a is a toothed disk fixed to the upright This disk u gears with a pinion2, mounted 1n the late 13. This pinion z carries a disk 1. In the caseof the instrument shown in the drawings the gear is so constructed thatthe disk 1 makes a complete revolution when the toothed disk 11., andconse uently the blade n, makes a quarter of a revo ution. A suitablescale from 0 to 90 is marked upon the surface of the disk 1, and apointer 2 is attached to the plate p to enable the angle to be read. Thesurface of the guide-bar a. is provided with suitable graduations, and 3is a double pointer attached to the plate 6 for enabling such plate tobe accurately adjusted in any position on the guide-bar a.

4 is astop, of which there are two, one on assist each end of theguide-bar e at the back, into contact with which the ends of the sidepiece g come, thus preventin the plate 6 from slidin entirely off theguir e-bar a.

he guide-bar a may in some cases be revided with a long dovetailed slotexten ing, if desired, the entire length of the said her. into this slotscales variously graduated may he slid, and the raduations on suchscales may be read wit facility by means fifths pointer 3. inserted intothe guide-bar a i or this purpose.

6 is a thumhpiece attached to the face of the plate 3) to facilitatemanipulation.

7 is a long strip of serrated metal attached to the upper edge of theblade 71. This strip may be suitably graduated to determine the positionof the teeth along the serrated edge. Under the blade n is a strip 8.This strip 8 is pivoted at 9 to a platelO at the end of the blade 71 bymeans of a screw-pivot provided with a fly-nut 11. The plate 10 may beprovided with graduations for determining angles.

12 is a handle by means of which the strip 8 may be conveniently turnedinto any required position.

13 is a pointer carried on the handle 12 for indicatin the position ofthe strip 8. The other en of the strip 8 from the pivot 10 is providedwith a metal stri 14, which takes under a catch 15 to hold t 1e strip 8in position when beneath the blade n. This catch 15 is closed toward theinner side to prevent the strip 8 passing right through. These detailsmay be seen in Figs. 2 and 3, Fig. 3 being inverted to more clearly showthe details.

It Will be observed that the strip 8 when in position under the blade74. projects slightly eyond the teeth upon the edge of the serratedstrip 7 in order to enable lines to be drawn. The edge of the strip 8may, if desired, be provided with a scale.

16 is a dovetail groove along the surface of the blade 12-, in whichslides a piece carrying a plate 1?. This plate 17 is provided withmarkings for determining angles and with in dentations 18 for thepurpose hereinafter mentioned. Instead of the flat plate 17, as shown atFl f. l, I may have a plate 19. (Shown clearly at Figs. 6 and 1 Thisplate is bent at right angles, so as to bring the portion 20 onto thelevel of the paper or the like on which the drawing is being done, andin this case the markings For determining the angles are provided on theportion 20.

21 is a steel strip attached to the plate 17 or 20 by means of a screwin attached to the plate 17 or 20, furnisher with a nut and rovided onits upper surface with. a suite ile scale. .23 is another steel strip,likewise provided with graduations and attached to the strip 21 by meansof a screw-pin and nut 24. At the bottom of this screw-pin 24 or on thestrip under same is a point 25 for use when it is required to strikecircles by means of the piece 23. The piece 23 may be provided with anysuitable number of holes 26, throu h which the point of a pencilrnay beplace when it is required to draw circles.

2? is a catch for taking over the piece 23 when it is turned back overthe piece 21. The piece 21 is provided with a suitable pointer 28 toenable the angles to be easily read, In Fig. 13 is shown a scale 5 being29 is a projection on the under surface of the strip 21 for taking intooi the indentations 18 on the plate I? or 20 for arresting the strip 21at intervalssay ten degrees apart.

30 is a slot through the blade 12., and 31 is a similar slot through thestrip 8. The slot 31 comes exactly beneath the slot 30 when the strip 8is in position beneath the blade a.

In considering the action of an instrument of the class described itwill be sufficient to explain some of the less obvious functions of theapparatus, since its uses are various that it would be impossible togive an ex haustive account of them. By loosening the handle r the bladea may be turned about the postf into any position with regard to theperpendiculari. a, with the guidebar a and looked in any required angle,as determined by the graduations on the disk 1, indicated by means ofthe pointer 2, and it may be locked in the position thus determined byagain tightening the handle 9. By loosenin the screw .9 the plate e mayhe slid up and down the guide-bar a, and the blade n can be bronghttoany required position without altering the angle formed by the bladewith the said guide-bar a. By again tightening the screw 8 the plate 6is secured in any required position on the said guide-bar. A series ofvertical parallel lines may be drawn by loos ening the screw .9, placingthe pencil in any one of the serrations at the edge of the strip 2, andsliding the plate 6 up and down the guidebar a. By means of the slot 30the operator is enabled to arrive at a vanishingpoint with restfacility. To do this, the screw .9 and t is handle 1 are loosened, sothat the plate 6 can slide up and down the uidebar a. A pin is passedthrough the s 0t 30 into the drawing-board, and by means of the lefthand the plate e is slid up and down. The lines then drawn can be madeto converge to the required point.

What I claim, and desire to secure by Letters Patent of the UnitedStates of America, ise 1. In a device of the character described, thecombination with a drawing-board, of a guide-bar attached to said board,a traveler mounted. on said bar, an arm attached to said traveler andextending at right angles to said guide bar, said arm having alongitudinal slot therein, a second traveler mounted in said slot, andarms pivotally connected to said second traveler, substantially asdescribed.

2. In a device of the character described, the combination with aguide-bar, of a traveler attached to said bar, an arm. attached to saidtraveler and provided with a longitudinal slot, a plate slidably mountedin said. slot and. one or more arms pivotally mounted on said plate andcooperating with said firstnamed arm, substantially as described.

3. In a device of the character described, a guidebar, a travelerslidably mounted on said bar, an arm connected to said traveler, meanswhereby said arm may be fixed at any desired angle, means forregistering the an gle, and an arm pivotally mounted on the under sideof said first-named arm and normally held in place by a clip,substantially as described.

4. In a device of the character described, a guide-b ar, a travelermounted on said guidebar, an arm carried by said traveler, a secondfixed at any desired angle, substantially as arm pivotally mounted onthe under side of i said first-named arm and normally held by a clipcarried by said arm, and means carried by said first-named arm forregistering the an le of said second-named arm, substantia ly asdescribed.

5. In a device of the character described, a guide-bar, a travelerslidably mounted on said guide-bar, comprising a base-plate,

frames attached to the under side of said baseplate and provided Withantifrictionrollers embracing said guide-bar, a pivotplate, an armattached to said pivot-plate, and an upwardly-extending shank integralwith said base-plate and extending throu h said pivot-plate whereby saidarm may% described.

6. In a device of the character described, a guide-bar, a travelerslidably mounted on said guide-bar comprising a base-plate, apivot-plate, an upwardly-extending hollow shank integral with saidbase-plate and extending throu b said pivot-plate, said shank beinginternal y threaded and having screwthreads formed on. its outer faceadjacent its upper end, a handle having an internallythreaded portionadapted to screw upon said shank to lock said pivot-plate, and athumbscrew having a milled head, said thumbscrew being adapted to en agewithin the threaded bore of said shant and lock said traveler upon saidguide-bar, substantially as described.

7. In a device of the character described, a guide-bar, a travelerslidably mounted on said guide-bar, comprising a base-plate, apivot-plate, an upwardly-extending shank integral with said base-plateand extendin through said pivot-plate, a gear-whee mounted on said shankand a registering disk carrying a pinion loosely mounted on saidpivot-pIate, said pinion being meshed with said gear-wheel whereby whensaid pivot-plate is moved to a desired angle the de ree of said anglemay be read, substantiaIly as described.

In testimony whereof I affix my signature in presence of two witnesses.

SIDNEY HERBERT DONA LDSON.

Witnesses:

H. D. JAMESON, A. NUTTINGV

